A hospital stay may trigger new health problems among elderly patients, according to a new study. / Getty Images/Pixland

by Liz Szabo, USA TODAY

by Liz Szabo, USA TODAY

For some elderly patients, a hospital stay may actually cause new health problems, making them sick enough to be readmitted within days or weeks of discharge, new research shows.

Nearly one in five hospitalized Medicare patients return to the hospital within 30 days.

Yet most of these patients return not because their previous illness has flared up, a new study suggests, but because they have an entirely new problem that, in many cases, was caused by the trauma of being hospitalized.

Patients initially hospitalized for pneumonia, for example, may become so weakened after a hospital stay that they fall and fracture a bone, says cardiologist Harlan Krumholz, a professor at Yale School of Medicine, who has written two new papers on the subject.

"They come into the hospital with one thing, but they leave with another," says Krumholz, whose study of Medicare patients appears in today's Journal of the American Medical Association. "Maybe what is going on is that people, through the hospitalization, are acquiring a new condition, something that makes them susceptible to a whole range of problems."

Among readmitted patients, 90% of those initially diagnosed with a heart attack came back with a different problem. So did 65% of the heart failure patients and 78% of the pneumonia patients, according to the study of more than 3 million hospitalizations, based on Medicare records.

Krumholz calls the phenomenon "post-hospital syndrome," a temporary period of increased vulnerability to all sorts of risks, from falls to heart attacks.

Many researchers are struggling to reduce medical errors and hospital-acquired infections, both of which can jeopardize patients' lives.

In this case, however, the problem is not poor hospital care or medical mistakes, but the routine difficulties of being a patient, says Krumholz. He also described post-hospital syndrome in a New England Journal of Medicine paper earlier this month.

For example, patients often don't sleep well in noisy, brightly lit hospital units. Nurses may interrupt their sleep to check vital signs or administer medication. Patients may not get enough to eat, especially if doctors order them to fast before procedures.

Patients often take sedating pain killers or others medications that can leave them confused, or even delirious, especially in the unfamiliar surroundings of a hospital. Lastly, extended bed rest can weaken patients' muscles and bones, Krumholz says.

"When you go through what most people go through in a hospitalization, you are impaired," he says. Even "if you took a healthy person through this, they would still be in a period of susceptibility" to health problems.

Even patients who are normally in good mental health can become psychotic in the hospital, from the combination of sleep deprivation, medications and stress, says physician Peter Pronovost, Johns Hopkins' senior vice president for patient safety and quality.

Patients in this state of mind are in no condition to understand discharge instructions, such as how to keep wounds clean or when to take medications, Pronovost says. It's easy to see how these patients can quickly deteriorate, he says.

Doctors also need to take a comprehensive view of patient wellness and preventing complications, Pronovost says.

"In the past, we worked to treat one thing and prevent one complication," Pronovost says. "But if you suffer one complication, you are at greater risk of another."

Krumholz says hospitals should try to address these issues, both before patients leave the hospital and in follow-up visits. In some cases, he says, it may be better for a patient to get a good block of sleep, rather than be awakened at 3 a.m. in order to administer a medication at the appropriate interval.

In analyzing the reasons why patients are readmitted, he says, "we haven't thought enough about the hospitalization, and how to make it less toxic, more healing and more soothing."

Patients and their caregivers also need to be aware of these increased risks during the first weeks after discharge. "We have to change from thinking, 'You're leaving the hospital so now you're better,' to thinking, 'You're really in phase two,' " Krumholz says. "This is a really dangerous period, and we have to make sure patients have a safe landing."

Some note that patients shouldn't be overly worried if they need to go to the hospital for a couple of days.

The problems Krumholz describes are more common among patients hospitalized for long periods, says David Shahian, research director at the Massachusetts General Hospital Center for Quality and Safety.

And while the problems are real, Shahian says he's not sure "whether it's something that deserves the title of a syndrome."

Secretary of State Hillary Clinton's recent health problems illustrate how a seemingly minor health issue can snowball, even outside the hospital. Clinton first suffered a gastrointestinal illness, which left her dehydrated and weak. That led her to fall and hit her head, causing a concussion. Trauma to the head then led to a blood clot in her head, causing her to be hospitalized.